.btn{
  position: relative;
  display: inline-block;
  font-weight: $btn-font-weight;
  line-height: $btn-line-height;
  color: $body-color;
  text-align: center;
  vertical-align: middle;
  background-image: none;
  border: $btn-border-width solid transparent;
  padding: $btn-padding-y $btn-padding-x;
  font-size: $btn-font-size;
  border-radius: $btn-border-radius;
  box-shadow: $btn-box-shadow;
  cursor: pointer;
  transition: $btn-transition;
  &.disabled,&[disabled]{
    cursor: not-allowed;
    opacity: $btn-disabled-opacity;
    box-shadow: none;
    > * {
      pointer-events: none;
    }
  }
}
.btn-default {
  @include button-style($white,$gray-400,$body-color,$white,$primary)
}
.btn-lg {
  @include  button-size($btn-padding-y-lg,$btn-padding-x-lg,$btn-font-size-lg,$btn-border-radius-lg)
}
.btn-sm {
  @include  button-size($btn-padding-y-sm,$btn-padding-x-sm,$btn-font-size-sm,$btn-border-radius-sm)
}
.btn-primary {
  @include button-style($primary,$primary,$white)
}
.btn-danger {
  @include button-style($danger,$danger,$white)
}
.btn-link {
  font-weight: $font-weight-normal;
  color: $btn-link-color;
  text-decoration: $link-decoration;
  box-shadow: none;
  background: none;
  &:hover{
    color: $btn-link-hover-color;
    text-decoration: $link-hover-decoration;
  }
  &:focus,&.focus{
    text-decoration: $link-hover-decoration;
    box-shadow: none;
  }
  &.disabled,&:disabled{
    color: $btn-link-disabled-color;
    pointer-events: none;
  }
}